Laser systems often require reshaping of the laser beam. Some of the rays of the laser beam may be separated or stripped from the beam of interest and the energy contained therein must be safely dissipated. In high power laser systems, such energy is substantial and the construction of a suitable heat absorbing device, commonly known as a laser dump, can present significant problems.
Many conventional laser dumps use a liquid coolant to absorb the incident radiant energy to keep the temperature of the dump material within allowable working limits. However, liquid cooling requires complex cooling channel networks and associated piping connections for the coolant. To increase the heat transfer rate, the coolant is usually forced through the cooling channels at a very high velocity under great pressure, which necessitates the use of a high pressure pump. U.S. Pat. Nos. 4,267,523 and 4,271,396 disclose laser dumps which utilize cooling fluids.
Other types of conventional laser dumps utilize reflective surfaces to control energy dissipation. One such design directs laser energy to a pointed reflective surface which reflects the energy to a hemispherical absorber. However, this design may result in excessive heat build up at the apex of the reflector. Another laser dump which utilizes reflective surfaces is disclosed in U.S. Pat. No. 4,511,216. This design controls the angles at which the beam is introduced to an internal cylindrical surface, and provides reflective and absorbing zones.